Roman around Kirkham - Signaculum Capsa Traditional Cache

What were seal boxes? That question has been raised more in recent years due to the fact that there still remains very little clear evidence as to their exact use.  The major theory at this point is that they were used to seal the string of a bound writing tablet.  Whereby the stings of the item were fed into the holes and sides eventually tied inside the hollowed area.  Wax was then poured onto the knot and then impressed with a seal from a ring.  This allowed the item to be secure and safely covered during transport.  One seal box has been found with the remnants of the bee's wax seal still inside of it. 

The reason that that things are not 100% defined is that in many locations very few seal boxes have been found, specifically in Pompeii.  It is believed that these seal boxes were in use more on the frontier and constituted part of the military mail system.  The frontier obviously had the vast majority of soldiers, specifically the ones stations at the forts on the northern front.